TW201350508A - Process for the manufacture of cyclic undecapeptides - Google Patents

Abstract

The present invention relates to processes and intermediates useful for the manufacture of cyclic undecapeptides, such as Alisporivir.

Description

Preparation method of cyclic undecyl acid peptide (UNDECAPEPTIDES)

The present invention relates to ring opening suitable for use in cyclosporin derivatives and subsequent use in the preparation of cyclic polypeptides, more particularly cyclic undecyl acid peptides such as alisporivir (also known as DEB025, Debio025 or Debio). Novel methods, novel process steps, and novel intermediates.

The present invention relates to a process for the preparation of a cyclic polypeptide such as a cyclic undecyl acid peptide such as alisporivir.

As described in WO 2006/038088, alisporivir is a cyclophilin (Cyp) inhibitor for the treatment of hepatitis C virus (HCV) infection or HCV-induced diseases. Furthermore, WO 2009/042892 describes a method for the treatment of multiple sclerosis by alisporivir; WO 2009/098577 describes a method for the treatment of muscle dystrophy by alisporivir; WO 2008/084368 describes rapavivir for the treatment of Ullrich type congenitality The method of muscle dystrophy.

WO 00/01715 describes alisporivir and its synthesis. Alippo has assigned CAS registration number 254435-95-5.

J.F. Guichoux in "De nouveaux analogues de Cycloposrine A comme agent anti-HIV-1" PhD thesis, Faculte des Sciences de L'Universite de Lausanne, 2002, in WO2006/038088 A method for the preparation of laboratory-scale alisporivir is described in WO 2008/084368.

The cyclic undecyl acid peptide shown below is a cyclic polypeptide of the formula (Ia) wherein n = 2.

Alaptop (Formula I) is a cyclic undecylamino acid peptide of formula (Ib) wherein n = 2, aa1 is D-MeAla and aa2 is EtVal.

n=2, aa ₁ = D-MeAla, aa ₂ = EtVal (Formula I)

General formula: Ring-(AXX1-AXX2-AXX3-AXX4-AXX5-AXX6-AXX-7-AXX8-AXX9-AXX10-AXX11) should cover cases from the fragmentation of the important Sar fragment, WO2010/052559 A1 Instance

AXX1=MeBmt, Bmt, MeLeu, Deoxy-MeBmt, Methylaminooctanoic acid

AXX2=Abu, Ala, Thr, Val, Nva

AXX3=Sar

AXX4=MeLeu, Val

AXX5=Val, Nva

AXX6=MeLeu, Leu

AXX7=Ala, Abu

AXX8=D-Ala

AXX9=MeLeu, Leu

AXX10=MeLeu, Leu

AXX11=MeVal, Val, D-MeVal, And all other combinations covered in WO 2010/052559 A1.

In recent years, cyclosporin A (CyA) has been used as a raw material for various synthetic cyclic undecapeptides suitable for the treatment of inflammatory or viral diseases. Cyclic undecaned acid peptides can be obtained by strain selection, however, obtaining the most natural derivatives requires chemical conversion, which relies on ring opening of a cyclic polypeptide such as formula (Ia) or (Ib) and subsequent amines Base acid substitution.

Conventionally, for example, a cyclic polypeptide of the formula (Ia) is ring-opened in a highly selective process and the amino acid residue is removed via an Edman degradation to obtain an open-loop ring as an important intermediate product. Polypeptide (Wenger, RM In Peptides 1996; Ramage, R., Epton, R. Ed.; The European Peptides Society, 1996, p. 173; Wenger, RM et al, Tetrahedron Letters 2000, 41, 7193.). Many scientists and companies have utilized this reliable and selective strategy in which pure cyclosporin A and purification by column chromatography have been used to obtain cyclic undecaned acid peptides.

Moreover, purification of the product, such as ring-opened cyclosporin A, involves several steps of purification by gelatin liquid chromatography. In addition to obtaining moderate overall yields, the main disadvantage of this purification scheme is the extremely high cost of the chromatography steps. Large-scale purification methods of such products derived from cyclosporin A or its structural analogs described in the literature generally involve chromatographic purification or at least one prior purification by adsorption chromatography. This pre-purification can be followed by, for example, extraction, countercurrent extraction, and/or supercritical fluid extraction.

However, due to the need for high quality, expensive precursors, none of these technologies It would be entirely satisfactory to obtain critical ring-opening intermediates at the desired quality requirements, at acceptable total yields, and at acceptable cost to industrial scale manufacturing.

We have found that dimethoxy carbon cations (described in the Novartis patent application EP 0 908 461 A1 for methylation of Cephalosporine derivatives) are in the ring opening of macrocyclic polypeptides. The same chemical process as the oxonium ion (trimethyl or triethyloxan Meerwein salt) was carried out. The novel conditions can advantageously be prepared in situ, thus avoiding the handling of toxic and hygroscopic materials, can be carried out in a variety of solvents such as toluene, xylene, aniline, without the use of undesirable chlorinated solvents such as methylene chloride. Or dichloroethane), and avoid the use of oxy-mirrion salts derived from genotoxic epichlorohydrin. Dedicated tetrafluoroborate carbon or a reactive species produced in situ by reaction of boron trifluoride with an orthoester derivative, preferably trimethyl orthoformate, produces the desired ring-opening polypeptide (such as the following compounds) 3).

We have found an improved method that maintains the advantages of a highly selective Edman degradation reaction strategy while taking advantage of the newly identified crystalline intermediates.

The following disclosure illustrates the novel open and crystalline intermediates derived from the ring opening of: cyclosporin A Cyclosporin B Cyclosporin D Cyclosporin G And a method for producing and purifying it via a method such as crystallization. The method allows for rapid, practical and more efficient obtaining of ring-opened cyclosporin A, cyclosporin B, cyclosporin D or cyclosporin G and for the preparation of cyclic undecyl acid peptides ( Such as Alippo). Moreover, the method according to the present disclosure can also be applied to other cyclosporins which can be opened by the same sequence. It has been found that a ring-opened cyclosporin salt such as hydrochloric acid (HCl), fluoroboric acid (HBF _{4 )} or hexafluorophosphoric acid (HPF ₆ ) can be formed in several stages.

The present invention provides novel crystalline intermediates such as cyclosporin esters such as acetate, pivalate, and ring-opened cyclosporin A, cyclosporin B, cyclosporin D or a ring A sporein G salt (such as an HCl salt, a HBF ₄ salt or an HPF ₆ salt), and a method of producing the same.

The present invention provides a method of preparing a compound of Formula 3 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl and R' is methyl or ethyl. The method comprises the steps of: thiolation of cyclosporin A to form acetamido-cyclosporin A; ring opening of ethyl-cyclosporin A; and ring-opening thiol- Cyclosporin A crystallizes to obtain a compound of formula 3.

The present invention provides a method of preparing a compound of Formula 4 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl and R' is methyl or ethyl. The method comprises the steps of subjecting a compound of formula 3 to Edman degradation; and then crystallizing the compound to obtain a compound of formula 4.

The present invention provides a method of preparing a compound of Formula 4 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl and R' is methyl or ethyl. The method comprises the steps of: thiolation of cyclosporin A to form acetamido-cyclosporin A; ring opening of ethyl-cyclosporin A; and ring-opening thiol- Cyclosporin A crystallizes to obtain a compound of formula 3 The compound of Formula 3 is subjected to Edman degradation; and the compound is then crystallized to obtain a compound of Formula 4 or a salt thereof.

The present invention provides a compound of the formula 3 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl and R' is methyl or ethyl.

The present invention provides a compound of the formula 4 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl and R' is methyl or ethyl.

Figure 1 is a proton NMR spectrum of Compound 3.

2 is a proton NMR spectrum of Compound 4.

The following reaction schemes show the general method according to the invention for the preparation of cyclic polypeptides, more particularly cyclic undecyl acid peptides, such as alisporivir; however, the general reaction scheme can also be used to prepare cyclic polypeptides. More specifically, a cyclic undecyl acid peptide derived from cyclosporin A, B, D or G.

Specifically, alisporivir can be prepared by thiolation of cyclosporin A to form acetyl-cyclosporin A (2); ring opening; crystallization to obtain compound 3, compound 3 Deman degradation reaction; crystallization to obtain compound 4 and cyclosporin A (compound (1) wherein R ² is ethyl) is converted to the compound of formula 4 shown above, and then compound 4 is cyclized to form Alappovir (shown below).

The invention is particularly directed to the methods described in the various sections. The invention is also independent of each single step described in the sequence of processes within the respective sections. Accordingly, each and every single step of any method described in the sequence of steps is a preferred embodiment of the invention. Accordingly, the present invention is also directed to such embodiments of the process whereby the compound obtained as an intermediate product in any step of the process is used as the starting material.

The invention is also directed to an intermediate product specifically developed for the preparation of a compound according to the invention, its use and a process for its preparation.

It should be noted that, in the present application, the explanations made in one section may also be applied to other sections unless otherwise stated.

Cyclosporin A, cyclosporin B, cyclosporin D or cyclosporin G can be prepared, for example, by a fermentation process.

In one embodiment, the invention relates to a process for the preparation of a compound of formula 3, which comprises the steps of: cyclosporin A, cyclosporin B, cyclosporin D or cyclosporin G thiol To form acetamido-cyclosporin A, B, D or G; ring opening; and crystallization.

In one embodiment, the invention relates to a compound of formula 4 or a salt thereof A process comprising subjecting a compound of formula 3 to an Edman degradation reaction (a reaction well known in the art) and crystallizing it to obtain a compound of formula 4.

Another embodiment of the invention is directed to a process for the preparation of a compound of formula 3 or formula 4 wherein the cyclosporin A starting material has a purity of > 80% by weight.

Another embodiment of the invention is directed to a process for the preparation of a compound of formula 3 or formula 4 wherein the cyclosporin A starting material has a purity of >85% by weight.

Another embodiment of the present invention is directed to a process for the preparation of a compound of Formula 3 or Formula 4 wherein the cyclosporin A starting material has a purity of from 60 to 80% (analyzed by weight).

Among the methods shown above, novel and inventive compounds are contemplated. Accordingly, other subject matter of the invention is the compounds shown below.

a compound of the formula 3 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl, R' is methyl or ethyl, and R ₂ is methyl, ethyl or propyl.

a compound of the formula 4 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl, R' is methyl or ethyl, and R ² is methyl, ethyl or propyl.

a compound of the formula 3 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl and R' is methyl or ethyl.

a compound of the formula 4 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl and R' is methyl or ethyl.

The following examples represent preferred embodiments of the reaction steps, intermediates, and/or methods of the invention and are intended to illustrate the invention without limiting its scope.

Preparation of Compound 3 HBF ₄ Salt Using Merwein Salt

Ethyl-cyclosporin A (100 g as present) was reacted with trimethyloxonium tetrafluoroborate (32 g) in dichloromethane (180 mL) at 20-25 °C. After 20 h, acetonitrile (200 mL) and water (650 mL) were added for hydrolysis. After 3 h, the phases were separated and the reaction mixture was dried by azeotropic distillation using 2-methyl-tetrahydrofuran (solvent exchange dichloromethane/2-methyl-tetrahydrofuran) at 20-25 °C. Then, the desired product was crystallized from 2-methyl-tetrahydrofuran (900 mL) and 2-methoxy-2-methylpropane (400 mL) to afford compound 3 HBF ₄ (63.9 g, dry After that, the purity was >92%). 0.69, (3H, d, J = 6.6 Hz); 0.71, (3H, d, J = 6.5 Hz); 0.81, (6H, m); [0.82..0.89], (24H, m); 0.90, ( 3H,d,J=6.6Hz);0.93,(3H,d,J=6.6Hz); 1.16,(6H,m);[1.23..1.50],(4H,m);1.52,(1H,m ); [1.32..1.73], (8H, m); 1.59, (3H, d, J = 6.0 Hz); 1.65, (2H, m); 1.65, 2.13, (2H, m); 1.93, 1.94, (3H, s); 2.03, (1H, m); 2.19, (1H, m); 2.45, (3H, s); 2.72, (3H, s); 2.84, (3H, s); 2.86, (3H , s); 2.99, (3H, s); 3.02, (3H, s); 3.06, (3H, s); 3.62, 3.68, (3H, s); 3.78, (1H, m); 3.87, 4.53, (1H, d, J = 17.2 Hz, 18.6 Hz); 4.10, 4.26, (1H, d, J = 18.6 Hz, 16.8 Hz); 4.23, (1H, m); 4.60, (1H, m); 4.62, (1H, m); 4.66, (1H, m); 5.02, (1H, m); 5.13, (1H, dd, J = 11.3 Hz, 4.7 Hz); 5.26, (1H, m); 5.29, (1H , m); 5.32, (1H, m); 5.36, (1H, m); 5.39, (2H, m); 7.72, (1H, d, J = 7.3 Hz); 8.14, (1H, d, J = 7.3 Hz); 8.21, 8.35, (1H, d, J = 7.3 Hz, 8.1 Hz); 8.85, (2H, s, br); 8.96, (1H, d, J = 8.4 Hz).

Preparation of Compound 3 HBF ₄ Salt by Trimethyl orthoformate and Boron Trifluoride

A solution of ethyl-cyclosporin A (10 g) in dichloromethane (20 mL) was added to a slurry of difluoroboric acid dimethoxycarbon at -15 ° C. It was produced by slowly adding boron trifluoride (2 ml) to a solution of trimethyl orthoformate (2 ml) in dichloromethane (20 mL) at 20 °C. After the addition, the slurry was allowed to warm to room temperature and kept stirring for 20 h. After that, acetonitrile (10 ml) and water (10 ml) were added. After stirring at 0 ° C for 2 h, the phases were separated. Next, after washing the organic phase with water, the solvent was replaced with 2-methyl-tetrahydrofuran and saturated with 2-methoxy-2-methylpropane to obtain Compound 3 as a white solid, which was dried under vacuum (5.1 g) , >90% purity) (see Figure 1).

Method for preparing compound HBF ₄ salt:

The previously prepared salt of compound 3 (34.62 g) was charged to the reactor along with sodium carbonate (4.8 g), toluene (50 mL) and water (50 mL). The resulting mixture was stirred at 20-25 ° C for 30 minutes and phase separated. Phenyl isothiocyanate (3.81 g) was added dropwise at 20-25 ° C over 1 h and the resulting reaction mixture was stirred until completion. Next, methanol (20 mL) and a 48% aqueous solution of fluoroboric acid (2.5 g) were added and the mixture was further stirred for 1 h. Then, water (25 mL) was added, and the phases were separated. The aqueous layer was extracted again with toluene (50 mL) and then extracted with 2-methyl-tetrahydrofuran (100 mL). The organic extract was azeotropically dried and the desired product was crystallised from 2-methyl-tetrahydrofuran (100 mL) and 2-methoxy-2-methylpropane (50 mL) to afford Compound 4 HBF ₄ as a white crystalline powder. (about 30 g, after drying, purity >93%). (See Figure 2).

0.69, (3H, d, J = 6.2 Hz); 0.73, (3H, d, J = 7.0 Hz); 0.81, (3H, t, J = 7.3 Hz, 7.3 Hz); 0.82, (3H, m); 0.85, (9H, m); 0.88, (6H, m); 0.91, (3H, d, J = 7.0 Hz); 0.93, (3H, d, J = 6.6 Hz); 0.99, (3H, d, J =7.0 Hz); 1.17, (6H, d, J = 6.6 Hz); [1.30..1.55], (9H, m); 1.60, (3H, d, J = 5.5 Hz); [1.56..1.72] , (4H, m); 1.93, 1.95 (3H, s); 2.09, (1H, m); 2.14, (1H, m); 2.20, (1H, m); 2.74, (3H, s); 3.06, (3H, s); 2.84, (3H, s); 2.87, (3H, s); 2.94, (3H, s); 3.02, (3H, s); 3.63, 3.68, (3H, s); 3.88, 4.52, (1H, d, J = 17.2 Hz, 18.6 Hz); 4.10, 4.24, (1H, d, J = 18.7 Hz, m); 4.24, (2H, m); 4.39, 4.62, (1H, m); 4.66, (1H, m); 5.02, (1H, m); 5.08, (1H, m); 5.26, (2H, m); 5.32, (1H, m); 5.37, (1H, m) ; 5.39, (2H, m); 7.84, 8.51 (1H, d, J = 7.3 Hz, 8.1 Hz); 7.98, (3H, s, br); 8.07, 8.18 (1H, d, J = 7.7 Hz, 7.3 Hz); 8.13, 8.27, (1H, d, J = 7.3 Hz, 8.1 Hz).

Alabome's method of production

The aforementioned intermediate product 4 (about 109 g) was added in portions to a mixture of toluene and sodium carbonate/water at 15 ° C and stirred at 15 ° C for 3 hours. Separate the aqueous phase. A dipeptide (about 28 g) and N-hydroxybenzotriazole monohydrate (8.1 g) were added at 0 °C. Water (2.5 mL) was added to the mixture and N-methylmorpholine (17.9 g) was added at -10 °C, followed by dosing at -10 °C to dicyclohexylcarbodiimide contained in toluene. A solution of the amine (21.9 g) was stirred at this temperature for 3 hours. The reaction mixture was heated to 0 °C over 10 hours. Upon completion, filter the reaction mixture and use 5% sodium carbonate solution, 5% salt solution, 2M hydrochloric acid and 10% salt solution The filtrate was extracted. The organic phase was again filtered and concentrated under vacuum at 50 °C.

Sodium borohydride (0.59 g) was dissolved in diethylene glycol dimethyl ether (14.3 g) at 20 to 40 °C. The turbid solution was cooled to 12-16 °C. Glycine (0.59 g) was added at this temperature. A solution of the previously prepared product (6.2 g) contained in about 6 g of toluene was added to the white suspension at 12-16 °C. Next, the reduction reaction was accelerated by adding methanol contained in toluene at 12-16 °C. This addition was controlled and carried out in 3 parts. Further, the reaction was stirred for 3 hours, and added to a stop solution (aqueous acetic acid solution) at an internal temperature of 10 to 20 °C. The rate of addition is consistent with hydrogen evolution (no accumulation). The phases were separated and the upper organic product phase was extracted with water and subsequently concentrated.

The previously prepared product (5 g) was dissolved in toluene (about 5 g) at 50 ° C and added to a solution of sulfuric acid (0.8 g) in methanol (50 mL) over a period of 40 to 60 minutes. After about 2 hours, the solution was cooled to 15-20 ° C and 25% benzyltrimethylammonium hydroxide (about 12 g) in methanol was added in an amount (exothermic reaction). After 2 hours, water was added in an amount and the mixture was stirred at 22 ° C for about 20 hours. Upon completion, the solution was cooled to 10-15 ° C, diluted with water and neutralized with dilute sulfuric acid. After separating the top toluene phase, the methanol of the bottom product phase is removed by distillation. The oily product was extracted with ethyl acetate and washed sequentially with water and a salt solution, and the pH was adjusted to 7.0-7.5 with dilute sulfuric acid. Next, the organic phase was azeotropically dried and then precipitated on cold heptane at 0-5 °C. The product suspension was filtered, washed with heptane and dried under vacuum at 60 °C.

The "undecyl-acid peptide amino acid" precursor (5 to 13% of the final total mass) dissolved in methylene chloride and DCC dissolved in methylene chloride were connected in parallel at 40 ° C for about 10 h. It was continuously added to a mixture of Cl-HOBT and NMM contained in dichloromethane. At the end of the addition, the mixture was additionally stirred for 2 h, filtered to remove the DCU salt and concentrated to give the crude product of alisporide.

Claims (16)

A method for preparing a compound of formula 3 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl, and R' is methyl or ethyl, the method comprising the steps of: cyclizing cyclosporin A to form acetyl-cyclosporin A; ring opening of acetamino-cyclosporin A; and crystallizing the ring-opened ethyl-cyclosporin A to obtain a compound of formula 3. The method of claim 1, which is used for the preparation of a compound of the formula 4 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl, and R' is methyl or ethyl, the process comprising the steps of: subjecting the compound of formula 3 to Edman degradation; and subsequently crystallizing the compound A compound of formula 4 is obtained. A method of preparing a compound of formula 4 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl, and R' is methyl or ethyl, the method comprising the steps of: i) cyclizing cyclosporin A to form acetamido-cyclosporin a bacteriocin A; ii) ring-opening ethyl-cyclosporin A; and iii) crystallizing the ring-opened ethyl-cyclosporin A to obtain a compound of the formula 3 or a salt thereof Iv) subjecting the compound of formula 3 to Edman degradation; and then v) crystallizing the compound to obtain a compound of formula 4 or a salt thereof. a compound of formula 3 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl, and R' is methyl or ethyl. a compound of formula 4 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl, and R' is methyl or ethyl. The method of claim 1 or 3, wherein the purity of the starting material is >80% by weight of cyclosporin A. The method of claim 6, wherein the purity of the starting material is >85% by weight of cyclosporin A. The method of claim 7, wherein the purity of the starting material is from 60 to 80% by weight percent of cyclosporin A. A method for preparing a compound of formula 3 or a salt thereof from cyclosporin A, cyclosporin B, cyclosporin D or cyclosporin G, Wherein R is methyl, ethyl, propyl or phenyl, R' is methyl or ethyl, and R ² is methyl, ethyl or propyl, the process comprising the steps of: cyclosporin A, B, D or G thiolated to form acetyl-cyclosporin A, B, D or G; ring opening of ethyl-cyclosporin A, B, D or G; The acetyl-cyclosporin A, B, D or G crystallizes to obtain a compound of formula 3. The method of claim 9, which is used for the preparation of a compound of the formula 4 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl, R' is methyl or ethyl, and R ² is methyl, ethyl or propyl, the process comprising the steps of: subjecting the compound of formula 3 to ed Mann degradation; and then the compound is crystallized to obtain a compound of formula 4. A method of preparing a compound of formula 4 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl, R' is methyl or ethyl, and R ² is methyl, ethyl or propyl, the process comprising the steps of: vi) cyclosporin A, B, D or G thiolated to form acetyl-cyclosporin A, B, D or G; vii) ring-opening ethyl-cyclosporin A, B, D or G; Viii) crystallizing the ring-opened ethyl-cyclosporin A, B, D or G to obtain a compound of the formula 3 or a salt thereof Ix) subjecting the compound of formula 3 to Edman degradation; and then x) crystallizing the compound to obtain a compound of formula 4 or a salt thereof. The method of claim 9 or 11, wherein the purity of the starting material is >90% by weight of cyclosporin A. The method of claim 12, wherein the purity of the starting material is >92% by weight of cyclosporin A. The method of claim 13, wherein the purity of the starting material is from 60 to 80% by weight percent of cyclosporin A. a compound of formula 3 or a salt thereof, (3) wherein R is methyl, ethyl, propyl or phenyl, R' is methyl or ethyl, and R ² is methyl, ethyl or propyl. a compound of formula 4 or a salt thereof, Wherein R is methyl, ethyl, propyl or phenyl, R' is methyl or ethyl, and R ² is methyl, ethyl or propyl.